Vacuum-tube apparatus



April 22, 1930. s, RUBEN y 1,755,272

VACUUM TUBE APPARATUS Filed Feb. 4, 1922 f ANODE 7/// improvedtype of vacuum tube apparatus in 'A which charges electrons through an evacuated space aiectedby electron impact in a manner utiions (if any) velement discharges. In the ordinary vacuum Patented pr.,22, 1930 -l UNITDASTATES PATENT-j l=1=lfC?"`-lj it. Y., Assieiron, BY mism'. Assicir'mrs, 'ro aunar santini. nuiamr, or New Yonx,

N. Y., a conronariou or DELAWARE ruim comm, or New Yonx,

` vacuum-rena nranarns* Y application n iea February' 4, i922. serial No. mais.

Thisinvention relates'to vacuum tube aparatus; and it relates more particularly to other emission element operating at substan- 'candescent .ilament ordinarily employed; a modulating element or grid being valso ordinarily included in the combination and serving to respond to variations in an operatively associated circuit, such as a radio l telegraph or telephone circuit,

thereby to modulate and. control the electron stream'in the evacuated chamber lothe an electron emission element y disto a plate element'that is responsive to or lizable to produce certain important results of novel and highly useul character.

The ordinary vacuum .tube orl thermionic relay commonly used at present comprises essentiall .three elements, namely, (a) a relay device Iorthe purpose of obtaininga. .source o electron emission, usually a tilasuitable'current in the relay circuit.

ment heated to incandescence, constituting a cathode-element; (7J) a modulating device in the form of a grid adaptedand arranged to control emission and to cause variations thereof; and (c) a'plate or anode element to which the emission from the filament or cathode apparatus constructed in accordance with the principles of this invention may take various forms provided itis responsive to theeiects of electron impact as above pointed out. In one desirable practical embodiment of the iiivention, the anode or plate element is wa selenium cell. In conjunction with the seleniumcell anode element, there is most ldesirably employed' as thev cathode .or source of tube device the plate oranode element functions simply as an electrode upon vvhichthe electrons are discharged from the filament and rom which the space current iows to the said filament or cathode element.'

I have discovered that the eiciency and sensitiveness of vacuum tube devices of this general type, such as an 'electron relay, can be materially increased by proper utilization of the kinetic energy f of the electrons and composing the discharge, which vantage of Iutilizing a filament of such properties residing in thefact that such a filament 'has in itselfless effect upon the special anodethan would an incandescent lainent .of the usual type. Between the said anode and cathode elements is interposed any suitable kinetic energy has been dissipated and wasted form of modulating grid. in such devices heretofore. The said kinetic In order to afford a full understanding o f energy or energy of electron impact upon the 11 as invention broadly by emlfilllcliying 'a' plate or plate element manifests itself in such forms heat of impact, (c)

l invention to utilize these several eiects vof the electron discharge in such manner' as to invention, by employing such an anodain conment thereof in an espec ally desirable practical form is illustrated in the accompanying and is hereinafter described in detail ,for the sake of a concrete illustrative example; but it is to be understood .that the invention is not limited to this particular arrangement or specific typeof apparatus.

In the drawings referred to, l

Fig. 1 is a more or'less diagrammatic representation of a vacuum tube device constructed in accordance with the present in-r vention, the view being a central section with certain parts shown in elevation;

as (a) low wave length light radiation, (b) mechanical pressure due to impact, (d) secondary electronic and ionic emission due to impact.

It is therefore a principal Aobject of the crease the eiliciency and sensitiveness of vdevices of this general description. This ob- `ject is attained in accordance with the present anode element that is use y responsive to suchfeiects ofelectronic impact; and also, Fig. 2 is a view of the selenium cell plate in the-most d able embodiment ofthe inor anode element viewed at right angles to Fig. 1;

The plate or anode element of vacuum tube which operates at a low red heat, the adfthe principles of the invention, one embodijunction with-a special'` typev oflmeffo.

tiallylower temperature than that of the in-y or the like, i

electron. emission an oxide coated filament Y here illustrated consists of a grooved porce- Fig. 3 is a circuit diagram illustrating the` employment of the novel device as an elec- 'tron relay in aradio receiving system.

Referring iirst more particularly to Figs. 1 and 2, 10 is an evacuated glass tube or bulb 1n whlchy are suitably mounted the elect-ron kemission element or cathode 11, the plate element or anode 12, and the modulating grid 13. In the present example the electron emission element llrconsists of an oxide-coated filament operating effectively at low red heat.

The plate or anode element is of such character as to be responsive to some or all of theltsf electron impact, especially the ei'ects hereinabove specifically referred to; and in the presentexample said anode consists of a selenium cell of the 'well known Bidwell type, a 'selenium cell being especially well adapted for the purpose. Generally de-i scribed, a selenium cell of this type andas lain body 14,- upon which are wound two copper wires that are spaced apart from each other, the windings being indicated generally at 15 and the separate leads to the4 respective insulated windings being indicated at 16 and y 17 and shown extending out through stem scribed serves admirably for the purposes of.

the invention because the 'impact of the electron stream from the lilament against the cell reduces the cell resistance materially by reason ofthe mechanical pressure of electron impact upon the cell, the low wave length light radiation produced, effect upon Vthe `cell. A thermolelectric current is also Produced as'a result of the heats ing effectotoith'e e ectron stream by potential across the cell. Itis to be noted that allthese factors f by some Aother circuit,

act inthe same-direction or' cumulatively; y

so thatfwhenthe 'relay circuit" is influenced I 4such as'a'radio receiving circuit, through the agency'ofthe modulatingfdevicefor grid, a large, response.

is caused in said relay circuit. Furthermore' the response .due Ito the 'peculiar' character ofthe anode or'fplate element can be added' 'tojor-superimposed'- upon theefect o r revspouse obtained theA 'ordinary electron` relay devicej-'othe-ltype A heretofore in yuse. j

While a seleniumcllfis @Specially dis-i1" and the heating Vhefimpact, and there is also -a .'secondary'emission discharge at rightangles .charged to the selenium a change in the current due to the effect of their reasongof this variation is able in practice to employ as the plate or anode element, particularly beause of its negative thermal coeficient of resistance, any other device responsive to some @or all of the various effects produced upon the anode by the vacuum tube discharge canbe utilized to realize the benefits of the invention inv whole or in part. VAmong other devices utilizable in this connection may be mentioned general types such'as a photo-electric cell, a sensitive thermo-electric couple, 'and a sensitive high resistance. A selenium cell such as that here illustrated embodiesthe characteristic functions of all three ofthese types, however, as already explained. Moreover, the invention is not limited to the employment of a heated filament as a source of electron emission or cathode element which may consist of any type of element of such character or so operated as to produce such emission either with orl without the use of heat.

i Fig. 3 illustrates in simple form an apvplication of the invention to a radio receiving system, where the lprimary circuit includes the antenna 26 and the variable primary 27 of the oscillation transformer connected to ground as shown, the variable condenser 28 being connected-across the primary inductance. The primary `27 energizesthc secondaryr 29 of the transformer, across which is connected the variable condenser 30, and variations in potential in the oscillatory `:ircuit thus constituted are impressed through condenser 31 upon the grid or modulating 100 `d'evice`13 of the electron relay device hereinabove described in detail. The filament 11 is heated by the battery B1, the heating cir- 'cuit including the variable resistance R. The

grid is connected, las shown, to the negative -side of battery B1. At B2 is the driving batv teryof the plate circuit. In addition, there is what may betermed a secondary plate circuit, in this instance the selenium cell circuit,

which as here shown includes the battery B2,

and a translating devicesuch as a telephone l. receiver Tr interposed between said battery and the selenium cell'. It will be seen that current iiow in this secondary selenium cell" circuit uctuates with changes in the selenium v115 cell resistance, -which changes result from varlations'- 1n the electron Astream flow efected by the grid. Referring to the operation in detail, it Willbe seen vthat when the filament 1l is heated to a dull red heat, it 12o .l

supplies electrons and ions which are discell plate. causing of the cell circuit impact upon-the y surface of the cell.A When the normal'potcm. YA125 tial of the grid 13 is altered by potential impressed upon it from the tuned secondary 're-4 -celvmg c1rcu1t 29, 30, thls causes variation in the volume of the electron stream; land by produced a'varia- IW)4 tion of enhanced amplitude in the secondary plate or cell circuit. In the circuit arrangement shown, variations in both the primary (emission discharge circuit) and the second- .ary anode (cell)l circuit areadded together torv 'plate element responsive to such impact or ombardment, specificallythe diaphragm of a m1crophone transmitter, the resultant vibrations of which, acting upon a carbon granule, produce variations in a batteryenergized secondary plate clrcuit analogous to that hereinabove described. The present application is therefore an impi'ovement on the deviceof said prior co-pending application; and it is to be understood that the type of apparatus disclosed in saidprior application is includedwithin the scope of corta'in of the broad claims hereto appended. While the device ofl said prior application thus embodies certain of the broad principles underlying the present improvements. it is not so eficient because it does not utilize the impact effect of electronemission to such an extent, and the present apparatus is accordingly deemed superior in practice.

In explaining the prlnciples of the invention, reference has been made more particuan evacuated receptacle, a ilamentary cath-l odeI in said receptacle, .and a selenium coated` for cooperation` with 'the cathode.

larly to an electron relay acting as an oscillation detector; but it is to be understood that the invention can be embodied in vacuum tube apparatus employed for other purposes such, for eXample ,-as apparatus for generating radio frequency currents. f

What I claim is:

v 1. Vacuum tube apparatus comprising an evacuated chamber containing an oxidecoated -filament constituting anode element. 1

ed filament constituting a` cathode element, and a selenium coated anode element.

6. A vacuumtube device containing an incandescible filament of high electron emissive properties at low luminosity, and a cooperating double terminal anode electrically rcsponsiveto light rays.

' 7. A space discharge device comprising a selenium coated anode member and an oxide coated incandescent filament, said filament being adapted to high electronic emission at low luminosity. y

8. A photo-electric cell comprising a sele-v nium coated anode member and an oxide coated incandescent filament, said filament being adapted to high electronic emission at low luminosity.

v9. An electron discharge device comprising an evacuated receptacle, a cathode in said receptacle, and a selenium coated anode in said receptacle in close proximity to the cathode and extending in spaced parallel relation thereto;

10. In 'an amplifying device a cath9de,a

grid for varying the stream of electrons finit-j.;A tedv by said cathode, and a two terminal light responsive anode having a negative temperature coefficient of resistance.

11. In an amplifying devlce a cathode adapted to operate at luminous temperature, a grid for varying the intensity of the electron emission from said cathode, and a two terminal anode designed to have a .current flow therethrough and being sensitive to variations in the intensity of radiations from the cathode including light to affect the current fiow therein.

12. An anode composed of s aced conductors normally electrically dls'connected and. bridged by material responsive to energy variations to vary the electrical conductivity of said anode.

In testimony whereof I hereunto affix my' signature.

SAMUEL RUBEN.

a cathode element, and a selenium cell constituting an 2. In a'vacuum tube device, the combination, with an electron emission element, of a.

cooperating anode elementcomprising a selenium cell. v y

3. An electron discharge device including anode in said receptacle 4. In-"alvacu'um tube device, the-combination,Av with an electron emission element, .of a

cooperating selenium-'coated .anode element.

5. Vacuum tube apparatus comprising an evacuated chamber containinganoxile-coat- 

